Docs: document 'manager' and '_log' attrs of logging.Logging (python#…

…108145)

Authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Doc/library/logging.rst

@@ -1019,6 +1019,14 @@ information into logging calls. For a usage example, see the section on
  'extra'. The return value is a (*msg*, *kwargs*) tuple which has the
  (possibly modified) versions of the arguments passed in.
 
+ .. attribute:: manager
+
+ Delegates to the underlying :attr:`!manager`` on *logger*.
+
+ .. attribute:: _log
+
+ Delegates to the underlying :meth:`!_log`` method on *logger*.
+
  In addition to the above, :class:`LoggerAdapter` supports the following
  methods of :class:`Logger`: :meth:`~Logger.debug`, :meth:`~Logger.info`,
  :meth:`~Logger.warning`, :meth:`~Logger.error`, :meth:`~Logger.exception`,